Battery-Powered Fan Controller Design
Worked for 1 min 25 sec
I found low-cost battery options: TP4056 charger, JST-PH LiPo connector, a buck-boost 3.3 V rail for the ESP32, and an optional 5 V boost stage for the fan if the fan must run from the battery.
Worked for 7 mins 41 sec
Implemented the first-pass schematic for a low-cost rechargeable LiPo thermocouple fan controller with ESP32-C6 BLE/Wi‑Fi, MAX31855 K-type thermocouple input, TP4056 USB-C charging, 3.3 V buck-boost regulation, and PWM fan drive with optional 5 V boost. I also added project docs: spec, bring-up plan, firmware notes, and regulatory/safety notes. Initial ERC-style checks came back with no open warnings/errors in the checked categories.
Open items:
- Confirm fan voltage/current and whether it must run fully from the internal battery.
- Confirm desired runtime and battery capacity.
- Decide whether phone-only UI is enough or if you want a small display.
- Confirm thermocouple connector style: screw terminal vs proper miniature thermocouple jack.
Suggested next steps:
- Pick the actual fan/blower and battery capacity.
- Add battery voltage measurement so the phone UI can show charge level.
- Move to PCB layout with antenna clearance and charger/boost thermal placement.
- Add a basic ESP32 firmware skeleton for BLE/Wi‑Fi provisioning, thermocouple readout, and fan PID control.
Set fan and battery
Use 5V blower
Add battery sensing
Start PCB layout
Check BOM cost
Phone-only UI
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Thermocouple Fan Controller Project Specification
Goal
Design a relatively low-cost, rechargeable battery-powered BBQ/smoker temperature controller inspired by the Big Green Egg EGG Genius: read a K-type thermocouple, compute temperature, and control a small blower fan with PWM.
Current Requirements
- Battery powered with USB-C recharging.
- Phone connectivity through Bluetooth Low Energy and/or Wi‑Fi.
- Low cost preferred over premium features.
- Sensor: K-type thermocouple through a cold-junction-compensated SPI converter.
- Fan: small external DC fan/blower, PWM switched, initially sized for up to about 1 A.
- MCU: ESP32-C6 class module to provide MCU + BLE/Wi‑Fi in one part.
- UI: basic local button and status LED; display deferred to keep cost down.
Revised Functional Blocks
- USB-C 5 V input for charging.
- Single-cell LiPo battery connector and charger/power-path.
- 3.3 V rail for ESP32-C6 and thermocouple converter.
- Optional fan supply boost path if the selected fan requires regulated 5 V from battery.
- ESP32-C6 wireless MCU module.
- Thermocouple connector and SPI thermocouple front-end.
- Low-side MOSFET fan driver.
- Programming/debug and basic user interface headers.
Cost Strategy
- Use ESP32-C6 for both control and BLE/Wi‑Fi; no separate radio.
- Keep UI minimal: phone app/web UI + one button + status LED.
- Prefer common charger/regulator parts and generic passives.
- Keep the first revision fan output flexible until fan voltage/current are confirmed.
Open Requirements
- Confirm fan rated voltage/current and airflow target.
- Confirm expected runtime per charge and approximate battery size.
- Confirm whether the fan must be powered from the internal battery or can use a separate external supply.
- Confirm thermocouple connector type: miniature thermocouple jack vs screw terminal.
- Confirm whether local display is required or phone-only UI is acceptable.
Goal
Current Requirements
Revised Functional Blocks
Cost Strategy
Open Requirements
